Historical clue formulations

• Learn secondhand — 2022-03-31
• Learn indirectly — 2019-07-13
• Be told about — 2010-10-28
• Learn secondhand — 2009-10-26
• Learn by word of mouth — 2009-06-21
• Learn about — 2004-08-31
• Learn in passing — 2003-06-26
• Learn by accident — 2002-04-26